cp's OEIS Frontend

A209343 Number of n-bead necklaces labeled with numbers -7..7 allowing reversal, with sum zero with no three beads in a row equal.

%I A209343 #6 Mar 12 2017 23:09:38
%S A209343 1,8,31,311,3045,34720,409199,5016681,62896466,803647811,10420410009,
%T A209343 136780924152
%N A209343 Number of n-bead necklaces labeled with numbers -7..7 allowing reversal, with sum zero with no three beads in a row equal.
%C A209343 Column 7 of A209344.
%e A209343 Some solutions for n=6:
%e A209343 .-5...-6...-7...-7...-3...-6...-7...-6...-6...-7...-7...-6...-7...-6...-5...-5
%e A209343 .-1....3...-2....0...-2...-5....3...-1...-3...-1...-2...-4...-5...-2...-4....0
%e A209343 .-1...-4....4...-1....7....6...-1....3....1....0....2....3....2....2....3....0
%e A209343 ..5...-1....5....0...-1....6...-1....4....3....4....1....3...-3....4...-1...-3
%e A209343 .-1....3...-7....1...-2...-2....1....0....4...-1....3....1....7...-5....2....2
%e A209343 ..3....5....7....7....1....1....5....0....1....5....3....3....6....7....5....6
%K A209343 nonn
%O A209343 1,2
%A A209343 _R. H. Hardin_, Mar 06 2012